Effects of Acute Cortisol Administration on Perceptual Priming of Trauma-Related Material

Intrusive memories are a hallmark symptom of posttraumatic stress disorder (PTSD). They reflect excessive and uncontrolled retrieval of the traumatic memory. Acute elevations of cortisol are known to impair the retrieval of already stored memory information. Thus, continuous cortisol administration might help in reducing intrusive memories in PTSD. Strong perceptual priming for neutral stimuli associated with a “traumatic” context has been shown to be one important learning mechanism that leads to intrusive memories. However, the memory modulating effects of cortisol have only been shown for explicit declarative memory processes. Thus, in our double blind, placebo controlled study we aimed to investigate whether cortisol influences perceptual priming of neutral stimuli that appeared in a “traumatic” context. Two groups of healthy volunteers (N = 160) watched either neutral or “traumatic” picture stories on a computer screen. Neutral objects were presented in between the pictures. Memory for these neutral objects was tested after 24 hours with a perceptual priming task and an explicit memory task. Prior to memory testing half of the participants in each group received 25 mg of cortisol, the other half received placebo. In the placebo group participants in the “traumatic” stories condition showed more perceptual priming for the neutral objects than participants in the neutral stories condition, indicating a strong perceptual priming effect for neutral stimuli presented in a “traumatic” context. In the cortisol group this effect was not present: Participants in the neutral stories and participants in the “traumatic” stories condition in the cortisol group showed comparable priming effects for the neutral objects. Our findings show that cortisol inhibits perceptual priming for neutral stimuli that appeared in a “traumatic” context. These findings indicate that cortisol influences PTSD-relevant memory processes and thus further support the idea that administration of cortisol might be an effective treatment strategy in reducing intrusive reexperiencing.     

Cultural Differences in the Relationship between Intrusions and Trauma Narratives Using the Trauma Film Paradigm

Two studies explored the influence of culture on the relationship between British and East Asian adults’ autobiographical remembering of trauma film material and associated intrusions. Participants were shown aversive film clips to elicit intrusive images. Then participants provided a post-film narrative of the film content (only Study 1). In both studies, participants reported intrusive images for the film in an intrusion diary during the week after viewing. On returning the diary, participants provided a narrative of the film (delayed). The trauma film narratives were scored for memory-content variables. It was found that for British participants, higher levels of autonomous orientation (i.e. expressions of autonomy and self-determination) and self-focus in the delayed narratives were correlated significantly with fewer intrusions. For the East Asian group, lower levels of autonomous orientation and greater focus on others were correlated significantly with fewer intrusions. Additionally, Study 2 found that by removing the post-film narrative task there was a significant increase in the number of intrusions relative to Study 1, suggesting that the opportunity to develop a narrative resulted in fewer intrusions. These findings suggest that the greater the integration and contextualization of the trauma memory, and the more the trauma memory reflects culturally appropriate remembering, the fewer the intrusions.     

Psychosocial Stress and 13‐year BMI Change Among Blacks: The Pitt County Study

Adverse psychosocial exposures may partially drive the high rates of obesity among blacks. The objective of this study was to prospectively examine the relationship between perceived psychosocial stress and percent change in BMI among adult black men and women. We used data from 756 women and 416 men who were participants in the Pitt County Study, a community‐based, prospective cohort study of blacks in eastern North Carolina. Participants were aged 25–50 years of age on entry into the study in 1988 and follow‐up was obtained in 2001. Using multivariable linear regression, we calculated the adjusted mean percentage change in BMI over the follow‐up period for each tertile of baseline measures of the Perceived Stress Scale (low, medium, and high), adjusted for potential confounders. For black women, higher levels of psychosocial stress at baseline predicted higher adjusted percentage increase in BMI over the 13‐year follow‐up: low stress 12.0% (95% CI 9.6–14.4), medium stress 16.3% (95% CI 13.7–18.9), and high stress 15.5% (95% CI 13.1–17.8). For black men, perceived stress was not associated with percent BMI change. These data suggest that interventions targeting obesity in black women should consider the potential impact of emotional stress on weight change.     

Acute pre-learning stress and declarative memory: impact of sex,cortisol response and menstrual cycle phase

This study explores the influence of pre-learning stress on performance on declarative memory tasks in healthy young adults in relation to sex and menstrual cycle phase. The sample was composed of 119 students (32 men and 87 women) from 18 to 25 years of age. The women were tested in different hormonal stages (30 in follicular phase, 34 in luteal phase, and 23 using oral contraceptives). The participants were exposed to the Trier Social Stress Test (TSST) or a control condition. Afterwards, their memory performance was measured using a standardized memory test (Rey's Auditory Verbal Learning Test). In the control condition, all groups of women recalled more words than men, but these differences disappeared in the group exposed to TSST because men's performance on the memory test improved, but only to the level of women. In addition, our data suggest that in women the relationship between cortisol and memory can be modulated by sex hormone levels, since in luteal women a negative relationship was found between memory performance and peak cortisol level. These results confirm that sex differences need to be considered in the relationship between pre-learning stress and memory performance.     

“Disorganized in time”: Impact of bottom-up and top-down negative emotion generation on memory formation among healthy and traumatized adolescents

“Travelling in time,” a central feature of episodic memory is severely affected among individuals with Post Traumatic Stress Disorder (PTSD) with two opposite effects: vivid traumatic memories are unorganized in temporality (bottom-up processes), non-traumatic personal memories tend to lack spatio-temporal details and false recognitions occur more frequently that in the general population (top-down processes). To test the effect of these two types of processes (i.e. bottom-up and top-down) on emotional memory, we conducted two studies in healthy and traumatized adolescents, a period of life in which vulnerability to emotion is particularly high. Using negative and neutral images selected from the international affective picture system (IAPS), stimuli were divided into perceptual images (emotion generated by perceptual details) and conceptual images (emotion generated by the general meaning of the material). Both categories of stimuli were then used, along with neutral pictures, in a memory task with two phases (encoding and recognition). In both populations, we reported a differential effect of the emotional material on encoding and recognition. Negative perceptual scenes induced an attentional capture effect during encoding and enhanced the recollective distinctiveness. Conversely, the encoding of conceptual scenes was similar to neutral ones, but the conceptual relatedness induced false memories at retrieval. However, among individuals with PTSD, two subgroups of patients were identified. The first subgroup processed the scenes faster than controls, except for the perceptual scenes, and obtained similar performances to controls in the recognition task. The second subgroup group desmonstrated an attentional deficit in the encoding task with no benefit from the distinctiveness associated with negative perceptual scenes on memory performances. These findings provide a new perspective on how negative emotional information may have opposite influences on memory in normal and traumatized individuals. It also gives clues to understand how intrusive memories and overgeneralization takes place in PTSD.     

Preliminary evidence that acute stress moderates basal testosterone's association with retaliatory behavior

A contribution to a special issue on Hormones and Human Competition.Testosterone is theorized to increase retaliation after social provocation. However, empirical evidence in support of these theories is mixed. The present research investigated whether acute stress causally suppresses testosterone's association with retaliation. We also explored sex differences in behavioral responses to acute stress. Thirty-nine participants (51.28% male) were randomly assigned to a high- or low-stress condition. Then participants engaged in 20 one-shot rounds of the ultimatum game, which was used to assess retaliatory behavioral responses to unfair treatment. Participants provided two saliva samples to measure testosterone and cortisol concentrations - one sample before the stress manipulation, and the second after the ultimatum game (20 minutes post-stressor). Results revealed a positive association between basal testosterone and retaliation in the low-stress condition, but not in the high-stress condition. Further, cortisol concentrations increased in the high- compared to the low-stress condition, and these cortisol changes moderated the association between basal testosterone and retaliation. The associations between basal testosterone and retaliation under varying levels of stress were similar in men and women. However, there was a sex difference in behavioral responses to the stress manipulation that was independent of testosterone. In women, the high-stress condition reduced retaliation compared to the low-stress condition, whereas in men the opposite pattern emerged. Collectively, this study (i) provides preliminary evidence that experimentally manipulated stress blocks basal testosterone's association with retaliation, and (ii) reveals a sex difference in retaliation under varying levels of stress. Discussion focuses on mechanisms, limitations, and the need for follow-up studies with larger sample sizes.     

Stress-Induced Cortisol Response and Fat Distribution in Women

Recent studies have shown an association between uncontrollable stress and abdominal fat distribution. It has been suggested that changes in cortisol secretion might represent one possible mechanism for this relationship. This study investigated whether body fat distribution, determined by waist-to-hip ratio (WHR), is related to salivary cortisol levels in response to laboratory stressors. Subjects were 41 overweight women with a Low or a High WHR. Multiple measures of cortisol and mood were obtained during a session of stressful tasks (eg., timed arithmetic) and during a time-matched, control rest session. Also, background life stress and psychological trait variables were assessed. Compared to Low WHR subjects, High WHR subjects secreted significantly more cortisol during the stressful session after 60 minutes of stress, and considering the total area under the curve of secretion. This difference was not seen on the rest day. In terms of background and psychological measures, High WHR subjects were characterized by poorer coping skills and differences in mood reactivity. Specifically, although all subjects became more angry in response to the stressful session, High WHR subjects showed smaller increases in anger. This could indicate that they are more likely to evidence a helpless reaction to uncontrollable stress. These findings support the hypothesis that cortisol secretion might represent a mechanism for the observed association between stress and abdominal fat distribution. Furthermore, differences in coping and appraisal may suggest that a particular psychological pattern might influence the reactivity of the adrenal-cortical system to stress, and subsequent fat distribution.     

Hippocampal damage abolishes the cortisol response to psychosocial stress in humans

The hippocampus (HC) is necessary for learning and memory, but it also plays a role in other behaviors such as those related to stress and anxiety. In support of the latter idea, we show here that bilateral HC damage abolishes the cortisol response to psychosocial stress. We collected salivary cortisol, heart rate, and affective responses to the Trier Social Stress Test (TSST) from 7 participants with bilateral HC lesions, 12 participants with damage outside the HC, and 28 healthy normal comparison participants matched to the HC participants on age and sex. HC participants showed elevated pre-stress cortisol, but no cortisol response to the TSST. Heart rate and affective responses in the HC group were similar to those of the comparison groups. Participants with brain damage outside the HC showed stress responses that were comparable to those of the healthy comparison group. These findings support the idea that the functions of the human HC extend beyond learning and memory, and suggest that the HC is necessary for producing the cortisol response to psychosocial stress.     

The role of salivary cortisol and DHEA-S in response to sexual, humorous, and anxiety-inducing stimuli

Stress and anxiety are commonly thought to be detrimental to sexual function. Several studies in both the human and animal literature, however, have found that inducing anxiety can enhance sexual function in women. The mechanisms that explain a negative relationship between physical and psychological stress and sexual functioning are well documented, but little is known about how stress or anxiety might have a facilitatory effect on sexual arousal. As an initial step in exploring the relationship between anxiety and sexual arousal, the present study examined the role of the autonomic nervous system, and the adrenal hormones cortisol and dehydroepiandrosterone-sulfate (DHEA-S) in response to a sexual film, an anxiety-inducing film, and a humorous film. Nineteen premenopausal women (mean age 24.4 years) who were free from sexual difficulties came into the lab on three separate days. At each session they were shown an anxiety-inducing, sexually arousing, or humorous (control) film while their physiological arousal was measured. They also provided saliva samples before and after each film. Cortisol significantly decreased, while DHEA-S increased in the sexual and humorous conditions. Neither hormone changed significantly in the anxiety-inducing condition. Autonomic nervous system activity measured by heart rate and heart rate variability did not change in response to the sexual or anxiety-inducing films, but heart rate variability increased significantly in response to the humorous film. The cortisol/DHEA-S ratio at the post-sexual film time point was significantly negatively correlated with genital arousal (measured by vaginal pulse amplitude). Anxiety-inducing films did not result in a physiological stress response, which can explain why they do not impair sexual function.     

New Episodic Learning Interferes with the Reconsolidation of Autobiographical Memories

It is commonly assumed that, with time, an initially labile memory is transformed into a permanent one via a process of consolidation. Yet, recent evidence indicates that memories can return to a fragile state again when reactivated, requiring a period of reconsolidation. In the study described here, we found that participants who memorized a story immediately after they had recalled neutral and emotional experiences from their past were impaired in their memory for the neutral (but not for the emotional) experiences one week later. The effect of learning the story depended critically on the preceding reactivation of the autobiographical memories since learning without reactivation had no effect. These results suggest that new learning impedes the reconsolidation of neutral autobiographical memories.     

Acute stress impairs recall after interference in older people,but not in young people

Stress has been associated with negative changes observed during the aging process. However, very little research has been carried out on the role of age in acute stress effects on memory. We aimed to explore the role of age and sex in the relationship between hypothalamus–pituitary–adrenal axis (HPA-axis) and sympathetic nervous system (SNS) reactivity to psychosocial stress and short-term declarative memory performance. To do so, sixty-seven participants divided into two age groups (each group with a similar number of men and women) were exposed to the Trier Social Stress Test (TSST) and a control condition in a crossover design. Memory performance was assessed by the Rey Auditory Verbal Learning Test (RAVLT). As expected, worse memory performance was associated with age; but more interestingly, the stressor impaired recall after interference only in the older group. In addition, this effect was negatively correlated with the alpha-amylase over cortisol ratio, which has recently been suggested as a good marker of stress system dysregulation. However, we failed to find sex differences in memory performance. These results show that age moderates stress-induced effects on declarative memory, and they point out the importance of studying both of the physiological systems involved in the stress response together.     

Sex differences in salivary cortisol in response to acute stressors among healthy participants, in recreational or pathological gamblers, and in those with posttraumatic stress disorder

Sex differences in incidence and severity of some stress-related, neuropsychiatric disorders are often reported to favor men, suggesting that women may be more vulnerable to aberrant hypothalamic-pituitary-adrenal (HPA) axis responses to stress. In this review, we discuss several investigations that we, and others, have conducted assessing salivary cortisol as a measure of HPA function. We have examined basal cortisol among healthy men and women and also following acute exposure to stressors. Among healthy participants, men had higher basal cortisol levels than did women. In response to acute stressors, such as carbon dioxide or noise, respectively, cortisol levels were comparable between men and women or higher among women. We have also examined cortisol levels among those with problem eating, gambling, or posttraumatic stress disorder (PTSD). Women with restrained eating habits have higher basal cortisol levels than do women without restrained eating habits. Pathological gamblers have more aberrant stress response to gambling stimuli than do recreational gamblers, and these effects are more prominent among men than women. Men who have motor vehicle accident related PTSD, demonstrate more aberrant cortisol function, than do their female counterparts. Although these sex differences in cortisol seem to vary with type of stress exposure and/or pathophysiological status of the individual, other hormones may influence cortisol response. To address this, cortisol levels among boys and girls with different stress-related experiences, will be the subject of future investigation.     

Interaction of Sleep and Emotional Content on the Production of False Memories

Sleep benefits veridical memories, resulting in superior recall relative to off-line intervals spent awake. Sleep also increases false memory recall in the Deese-Roediger-McDermott (DRM) paradigm. Given the suggestion that emotional veridical memories are prioritized for consolidation over sleep, here we examined whether emotion modulates sleep’s effect on false memory formation. Participants listened to semantically related word lists lacking a critical lure representing each list’s “gist.” Free recall was tested after 12 hours containing sleep or wake. The Sleep group recalled more studied words than the Wake group but only for emotionally neutral lists. False memories of both negative and neutral critical lures were greater following sleep relative to wake. Morning and Evening control groups (20-minute delay) did not differ ruling out circadian accounts for these differences. These results support the adaptive function of sleep in both promoting the consolidation of veridical declarative memories and in extracting unifying aspects from memory details.     

Social cognition under stress: Differential effects of stress-induced cortisol elevations in healthy young men and women

Humans as social beings often have to perform complex social cognitive tasks while under stress (e.g., during a social conflict). Previous research has established that the brain regions responsible for social cognitive tasks are target regions for stress hormones. However, little experimental research has been done testing the acute effects of stress on social cognition. Here, we investigated whether stress exposure and the ensuing glucocorticoid (i.e., cortisol) elevations affect social cognition. Thirty-two men and 32 women were exposed to either a psychosocial stress or a non-stressful control test before assessing their social cognition using the Reading the Mind in the Eyes Test (RMET) and the Movie for the Assessment of Social Cognition (MASC). Results showed differential effects of stress-induced cortisol responses among men and women for the MASC, but not the RMET. Among men, high cortisol responders displayed elevated MASC scores compared with low cortisol responders. Moreover, for stressed men a positive association between the magnitude of the cortisol responses to the stressor and MASC scores emerged. Among women, enhanced MASC scores were found for low cortisol responders relative to high cortisol responders and non-stressed controls. A strong negative association between cortisol reactivity and MASC scores was found among women. These results imply sex specific effects of glucocorticoids on social cognition and partially support the idea of sex differences in biobehavioral stress responses, with men engaging in fight-or-flight responses while women may react to stress with tending and befriending behavior.     

Updating versus Exposure to Prevent Consolidation of Conditioned Fear

Targeting the consolidation of fear memories following trauma may offer a promising method for preventing the development of flashbacks and other unwanted re-experiencing symptoms that characterise Posttraumatic Stress Disorder (PTSD). Research has demonstrated that performing visuo-spatial tasks after analogue trauma can block the consolidation of fear memory and reduce the frequency of flashbacks. However, no research has yet used verbal techniques to alter memories during the consolidation window. This is surprising given that the most effective treatments for PTSD are verbally-based with exposure therapy and trauma-focused cognitive behavioural therapy gaining the most evidence of efficacy. Psychological therapies aim to reduce the conditioned fear response, which is in keeping with the preliminary finding that an increased propensity for fear conditioning may be a vulnerability factor for PTSD. Our research had two aims. We investigated the degree to which individual differences in fear conditioning predict the development of PTSD symptoms. We also compared the preventative effects of two clinically informed psychological techniques administered during the consolidation window: exposure to the trauma memory and updating the meaning of the trauma. 115 healthy participants underwent a fear conditioning paradigm in which traumatic film stimuli (unconditioned stimuli) were paired with neutral stimuli (conditioned stimuli). Participants were randomly allocated to an updating, exposure or control group to compare the effects on the conditioned fear response and on PTSD symptomatology. The results showed that stronger conditioned responses at acquisition significantly predicted the development of PTSD symptoms. The updating group, who verbally devalued the unconditioned stimulus within the consolidation window, experienced significantly lower levels of PTSD symptoms during follow-up than the exposure and control groups. These findings are consistent with clinical interventions for chronic PTSD and have important implications for identifying those at risk as well as for designing novel early interventions to prevent the development of PTSD.     

Psychopathic personality traits and cortisol response to stress: The role of sex, type of stressor, and menstrual phase

Previous research indicates that psychopathic personality traits are associated with lower cortisol secretion in response to stress in men but not in women. The current study explored whether prior null results for women were related to the latency of the cortisol stress response to two different types of stressors. Additionally, accuracy of self-reported menstrual phase was explored via salivary progesterone levels. A mixed-sex sample of 145 participants characterized by high (36 men, 37 women) and low (34 men, 38 women) scores on a screening measure of psychopathic personality traits were randomly assigned to either a performance-based stressor task or a social rejection stressor task. Salivary hormone samples were taken just prior to task onset (baseline) and at 0, 20, 40, and 60 min post-stressor. Results indicated that both men and women characterized by psychopathic personality traits exhibited lower stress-induced cortisol levels to the performance-based task in comparison with controls at 20 min post-stressor. The social rejection task produced a cortisol response 20 min post-stressor in the male controls only. Removal of women with low progesterone from the analyses strengthened the psychopathy group differences. Results could suggest that deficient cortisol production in response to stress might be another important neurobiological feature associated with psychopathic traits, and that biological verification of menstrual phase is an important aspect to obtaining accurate cortisol results in women.     

Plasma cortisol in men--relationship with atherosclerosis of retinal arteries

The production of cortisol increases in acute stress but the effects of chronic stress on plasma cortisol are still controversial. Stress on the other hand plays a role in coronary artery disease (CAD) and carotid atherosclerosis. Since there is no data about plasma cortisol and atherosclerosis of the retinal arteries, the purpose of this study was to explore the relationship between plasma cortisol in 101 adult males with the degree of their retinal vessels atherosclerosis. The results were compared with those in 47 matched apparently healthy men with no retinal vessels changes. The atherosclerotic changes of retinal vessels were determined by direct ophthalmoscopy and graded (1-4) according to Scheie. Morning plasma cortisol levels were determined by radioimmunoassay using commercial kits. The results were compared by using chi-square test. No association between morning plasma cortisol concentrations and retinal vessels atherosclerosis could be found. The results of this study do not support a role for physiological levels of plasma cortisol in the development of atherosclerosis, at least of the retinal arteries, in men.     

Sexy thoughts: effects of sexual cognitions on testosterone, cortisol, and arousal in women

Previous research suggests that sexual stimuli increase testosterone (T) in women and shows inconsistent effects of sexual arousal on cortisol (C), but effects of cognitive aspects of arousal, rather than behaviors or sensory stimuli, are unclear. The present study examined whether sexual thoughts affect T or C and whether hormonal contraceptive (HC) use moderated this effect, given mixed findings of HC use confounding hormone responses. Participants (79 women) provided a baseline saliva sample for radioimmunoassay. We created the Imagined Social Situation Exercise (ISSE) to test effects of imagining social interactions on hormones, and participants were assigned to the experimental (sexual) or one of three control (positive, neutral, stressful) conditions. Participants provided a second saliva sample 15 min post-activity. Results indicated that for women not using HCs, the sexual condition increased T compared to the stressful or positive conditions. In contrast, HC using women in the sexual condition had decreased T relative to the stressful condition and similar T to the positive condition. The effect was specific to T, as sexual thoughts did not change C. For participants in the sexual condition, higher baseline T predicted larger increases in sexual arousal but smaller increases in T, likely due to ceiling effects on T. Our results suggest that sexual thoughts change T but not C, baseline T levels and HC use may contribute to variation in the T response to sexual thoughts, and cognitive aspects of sexual arousal affect physiology.     

Emotional intelligence and oscillatory responses to emotional facial expressions

Emotional intelligence-related differences in oscillatory responses to emotional facial expressions were investigated in 48 subjects (26 men and 22 women), age 18–30 years. Participants were instructed to evaluate emotional expression (angry, happy, and neutral) of each presented face on an analog scale ranging from ?100 (very hostile) to + 100 (very friendly). High emotional intelligence (EI) participants were found to be more sensitive to the emotional content of the stimuli. It showed up both in their subjective evaluation of the stimuli and in a stronger EEG theta synchronization at an earlier (between 100 and 500 ms after face presentation) processing stage. Source localization using sLORETA showed that this effect was localized in the fusiform gyrus upon the presentation of angry faces and in the posterior cingulate gyrus upon the presentation of happy faces. At a later processing stage (500–870 ms), event-related theta synchronization in high emotional intelligence subjects was higher in the left prefrontal cortex upon the presentation of happy faces, but it was lower in the anterior cingulate cortex upon the presentation of angry faces. This suggests the existence of a mechanism that can selectively increase the positive emotions and reduce negative emotions.     

Blunted cortisol response to acute pre-learning stress prevents misinformation effect in a forced confabulation paradigm

Research examining the effects of stress on false memory formation has been equivocal, partly because of the complex nature of stress-memory interactions. A major factor influencing stress effects on learning is the timing of stress relative to encoding. Previous work has shown that brief stressors administered immediately before learning enhance long-term memory. Thus, we predicted that brief stress immediately before learning would decrease participants' susceptibility to subsequent misinformation and reduce false memory formation. Eighty-four male and female participants submerged their hand in ice cold (stress) or warm (no stress) water for 3 min. Immediately afterwards, they viewed an 8-min excerpt from the Disney movie Looking for Miracles. The next day, participants were interviewed and asked several questions about the video, some of which forced them to confabulate responses. Three days and three weeks later, respectively, participants completed a recognition test in the lab and a free recall test via email. Our results revealed a robust misinformation effect, overall, as participants falsely recognized a significant amount of information that they had confabulated during the interview as having occurred in the original video. Stress, overall, did not significantly influence this misinformation effect. However, the misinformation effect was completely absent in stressed participants who exhibited a blunted cortisol response to the stress, for both recognition and recall tests. The complete absence of a misinformation effect in non-responders may lend insight into the interactive roles of autonomic arousal and corticosteroid levels in false memory development.